AWS::AutoScaling::AutoScalingGroup InstancesDistribution

InstancesDistribution is a subproperty of MixedInstancesPolicy that describes an instances distribution for an Auto Scaling group. The instances distribution specifies the distribution of On-Demand Instances and Spot Instances, the maximum price to pay for Spot Instances, and how the Auto Scaling group allocates instance types to fulfill On-Demand and Spot capacity.

For more information, see Auto Scaling Groups with Multiple Instance Types and Purchase Options in the Amazon EC2 Auto Scaling User Guide.

Syntax

To declare this entity in your AWS CloudFormation template, use the following syntax:

JSON

{
  "OnDemandAllocationStrategy" : String,
  "OnDemandBaseCapacity" : Integer,
  "OnDemandPercentageAboveBaseCapacity" : Integer,
  "SpotAllocationStrategy" : String,
  "SpotInstancePools" : Integer,
  "SpotMaxPrice" : String
}

YAML

  OnDemandAllocationStrategy: String
  OnDemandBaseCapacity: Integer
  OnDemandPercentageAboveBaseCapacity: Integer
  SpotAllocationStrategy: String
  SpotInstancePools: Integer
  SpotMaxPrice: String

Properties

OnDemandAllocationStrategy

Indicates how to allocate instance types to fulfill On-Demand capacity.

The only valid value is prioritized, which is also the default value. This strategy uses the order of instance type overrides for LaunchTemplate to define the launch priority of each instance type. The first instance type in the array is prioritized higher than the last. If all your On-Demand capacity cannot be fulfilled using your highest priority instance, then the Auto Scaling groups launches the remaining capacity using the second priority instance type, and so on.

Required: No

Type: String

Pattern: [\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*

Update requires: No interruption

OnDemandBaseCapacity

The minimum amount of the Auto Scaling group's capacity that must be fulfilled by On-Demand Instances. This base portion is provisioned first as your group scales.

The default value is 0. If you leave this property set to 0, On-Demand Instances are launched as a percentage of the Auto Scaling group's desired capacity, per the OnDemandPercentageAboveBaseCapacity setting.

Note

An update to this property means a gradual replacement of instances to maintain the specified number of On-Demand Instances for your base capacity. When replacing instances, Amazon EC2 Auto Scaling launches new instances before terminating the old ones.

Required: No

Type: Integer

Update requires: Some interruptions

OnDemandPercentageAboveBaseCapacity

Controls the percentages of On-Demand Instances and Spot Instances for your additional capacity beyond OnDemandBaseCapacity.

The range is 0–100. The default value is 100. If you leave this property set to 100, the percentages are 100% for On-Demand Instances and 0% for Spot Instances.

Note

An update to this property means a gradual replacement of instances to maintain the percentage of On-Demand Instances for your additional capacity above the base capacity. When replacing instances, Amazon EC2 Auto Scaling launches new instances before terminating the old ones.

Required: No

Type: Integer

Update requires: Some interruptions

SpotAllocationStrategy

Indicates how to allocate Spot capacity across Spot pools.

If the allocation strategy is lowest-price, the Auto Scaling group launches instances using the Spot pools with the lowest price, and evenly allocates your instances across the number of Spot pools that you specify. If the allocation strategy is capacity-optimized, the Auto Scaling group launches instances using Spot pools that are optimally chosen based on the available Spot capacity.

The default is lowest-price.

Valid values: lowest-price | capacity-optimized

Required: No

Type: String

Pattern: [\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*

Update requires: No interruption

SpotInstancePools

The number of Spot pools to use to allocate your Spot capacity. The Spot pools are determined from the different instance types in the Overrides array of LaunchTemplate. The range is 1–20. The default value is 2.

Valid only when the Spot allocation strategy is lowest-price.

Required: No

Type: Integer

Update requires: No interruption

SpotMaxPrice

The maximum price per unit hour that you are willing to pay for a Spot Instance. If you leave the value of this property blank (which is the default), the maximum Spot price is set at the On-Demand price.

Required: No

Type: String

Minimum: 0

Maximum: 255

Update requires: No interruption